You wouldn't be the only person to think so.
However, aikido is a tremendously powerful mode of subconscious communication. Seagal's films are a despicable use of that powerful tool and gift. It's just like Jim and Tammy Bakker or any other person who misuses The Bible to make money for themselves. It's evil. It's the equivalent of prostituting aikido, and his positition would equate to the pimp in that simile. I hate to see a great art used that way. And that is real life.
I think that this is really dependant on personal views. I have not yet seen any forms of "subconcious communication" in aikido, whatever that might be.
Why should one not be allowed to use something one is very proficient at-in this case: aikido- to earn some money, while at the same time recruit new members for the aikido family? If I'm not mistaken, a whole lot of Japanese masters do exactly the same: they travel around the world giving seminars, and people often have to pay a lot in order to attend. I'm even happy for them, because very few people actually manage to make their passion their main source of income.
"A great art" is, again, subjective. What we find in aikido, others may find in Judo, Tae Kwon Do, personal religion or even their daily job. Aikido is not some kind of be-all end-all religion/thingy. It's a martial art. The main focus should always be on the martial. I know dojos who don't spend a second on the spiritual side of aikido and choose to focus only on the techniques. I have also read about dojos incorporating christian elements and teachings in their aikido (mainly in the US). It's really up to the instructor, what his beliefs are, and what he finds useful for his students. However, I believe that as a student, the biggest part is up to you. You have to discover for yourself what is of use to you, and what isn't, and you won't necessarily discover that in aikido. It's all very subjective.