I grew up in a union family (IBEW 494) and worked for a time in the Milwaukee Carpenter's union, had non-union jobs in unionized businesses, and have encountered many others over the years. I don't have problems with unions generally. But I do believe there should be changes.
The simplist way I say it is that I'd like to see all workers represented, not just the select few. There are plenty of businesses that take advantage of cheap labor. (and, please, note that there are many, many that don't!) The workers either don't have a voice in how they are treated, or don't realize that they can use their voice. I would like to see those workers represented so they get a fair shake from life. And there are union shops that end up paying employees a great deal... sometimes three to four times as much as non-unionized people doing comparable work. I'd like them less represented. There must be some way to achieve a reasonable balance.
I only have the vaguest notion of how to go about accomplishing such a thing, which would likely have to start on at least the state level, with a mandated program involving paychecks, probably along the lines of a withdrawals. In any case, it's a lot bigger thing to consider than I'm currently capable of, so, other then the basic thought that I'd support it if things started heading that-a-way, I'm not going to invest a lot of time in it.