I have found Ruger stocks to be on a par with most other factory synthetic stocks. They are as good as the price-point will allow.
"Flimsy" is a subjective term. No, they aren't as stiff as a high-end kevlar/graphite aftermarket item, but they aren't priced that way, either.
As far as being too soft for glass bedding, that's hooey! They will hold a glass bedding job as well as any other. If it is done right, there isn't a problem. And. if it is done wrong, it won't hold up on any stock, regardless of price. Proper preparation is a must.
All that said, do I like them? Well, I just don't know. As with the Remington model-7, I thought the early Ruger stocks were just too ugly for words... Now, I kinda like them. It took a lotta years for my taste to change. Now that Ruger is using "full profile" stocks, I'll probably take a few more years to make up my mind!
How's that for a definite maybe?