I'd wager you haven't seen any games this season if you're being truthful. His toughness was questioned because he was always rail-thin, as many 18 year olds are. However with the added weight and maturity, his rebounding and toughness has improved. He's been much more physical this year and it's crystal clear he has benefited from the improved strength. If you want to act like his past lack of strength hasn't been improved upon, go ahead. He's not a physical specimen, and some of his game takes place away from the basket, but he's not soft. He's much tougher than the likes of Bargnani and Frye.
Your problem is you directly equate rebounding in Europe to the NBA. Doesn't work like that as I've already pointed out. It's much easier to rack up stats in the NBA. Rubio should be evidence enough of this - I insisted that his low assist numbers in Europe were not at all indicative of his future numbers in the NBA and many ignored it. Well, it's the same deal with rebounding. Marc Gasol, in his last three years in Europe, averaged a whopping 5, 6, and 8 rebounds respectively. He seems to be rebounding just fine in the NBA, don't you think?
How about his older brother? Averaged 6 in Europe, comes over and is straight into double figures. Scola's numbers also improved after making the transition. Gortat averaged 5.6 boards a game before coming over (now averaging 10). I could go on and on but there really is no point. You can't look at rebounding numbers in Europe and decide they will do the same in the NBA, it's idiotic. I'm not even saying Motiejunas will be a very good rebounder, I'm not even saying we should trade for him, I'm just sick and tired of the same stuff that's spouted regardless of accuracy.