I've been using Reason since the days of Reason 1.0!
Without Reason, I wouldn't be working as a producer/engineer right now.
Reason is a very powerful tool and I know why some people have a dim view on it!
Hours of programming and software development went into Reason to make it a 'virtual studio.' Because of these great efforts, producing music became (almost) effortless since you can make music in the comfort of your own home. In some people opinion, too easy to use = unprofessional. In my opinion, the development behind this software is amazing.
I still think that Reason is one of the easiest pieces of software to expand and make even more powerful (eg adding your own kits/samples etc).
Secondly, Reason is still 'software.'
I've known producers to assume that synths etc should be pure hardware whereas some sequencers should be software. Reason is available to download illegitimately for free, therefore some producers feel that people using Reason think they've become bedroom producers overnight!
My personal view is this: Reason has the ability to make almost any sound you can think of. It's just how you use it that can make Reason give you a mainstream release ready quality to a beginers bedroom quality.
Just because it's easy to get what you want, doesn't make this a kids toy!!
Reason is still today my favourite software!