I am not extremely familiar with the intricacies of Marxist ideology but many of these articles seem to suggest that classical Communist ideology perceives the bourgeoisie as the 'real enemy of the proletariat', even though these political philosophies evolved when monarchy and the land-owning aristocracy was very much in greater dominance all over Europe including Russia.
The Communist antagonism against the bourgeoisie continues to this day, including in the part of South India where I live [where Communism is a 'religion' for a significant section of the population, Marxist ideological education is widespread for interested individuals at local level, employee and trade unions are predominantly communist, and Communist governments regularly ascend to provincial rule through democratic elections. See 'update' at the end of this question to read what Uncle said.]
Political changes mostly unrelated to communism have admittedly reduced the erstwhile aristocracy, all over the world including in India, to the status of 'rich or very rich citizens still owning substantial land, and having significant traditional influence but no political authority.'
In most modern nations (excluding a few Communist states and dictatorships) the real political power is now wielded by elected representatives of the people, but Communism continues to be strongly antagonistic to the bourgeois class.
The nearest explanation I could get (which does not fully explain the case) comes from the Wikipedia article on Bourgeoisie --
[Bourgeoisie:] a sociologically defined class, especially in contemporary times, referring to people with a certain cultural and financial capital belonging to the middle or upper stratum of the middle class: [...] an affluent and often opulent stratum of the middle class (capitalist class) who stand opposite the proletariat class.
In Marxist philosophy the bourgeoisie is the social class that came to own the means of production during modern industrialization and whose societal concerns are the value of property and the preservation of capital, to ensure the perpetuation of their economic supremacy in society.
Note that between the period of the development of Marxist theory and the Russian Revolution, both the European monarchs and the land-owning aristocrats were still the real powers in society, in that they wielded traditional, political, legal, administrative and military authority, especially in the Russian Empire, while the bourgeoisie has never been more than a (very influential) economic powerhouse, and only relatively recently, since the Industrial revolution.
Considering that classical communist ideology evolved in this political and social atmosphere,
for what stated reasons (not a matter of opinion, remember) does classical communism consider the bourgeoisie -- even more than the aristocacy -- to be the real enemies of the People?
(Note: I am a sociologist, not a political scientist; and 'Classical communism' as used here refers to the original Marxist theory that was put into practice in and after the Russian Revolution, as distinct from various re-interpretations of this ideology that have later been attempted all over the world.)
Update: today I met an 82 year old 'uncle' (very close family friend) who belongs to the land-owning 'administrative upper caste' that used to ruthlessly enforce the traditional authority of the aristocracy in parts of South India right up until major political changes created the first elected Communist (provincial) government 60 years ago. Uncle said:
I was 22 years old at the time and India has come a long way in these 60 years, but Communists, who were responsible for major socio-economic reforms in this region, still tend to accuse me of being bourgeoisie. I tell them that this is a very different world now -- I have no special privileges nor any feeling of caste- or class-superiority: I am no more bourgeoisie than you or OP!
Class conflict will never end till there is capitalism in the world, the uncle said.