TedSlimm has posted about it multiple times and ive since bought in: left tackle has never been more devalued then it is now. Defenses are loading up on interior pass rushers and franchises are protecting their quarterbacks in different ways then in the past, such as roll outs and quick throws. Its one of the reasons why slot receivers and tight ends have become essential to every franchise.
Another thing people havent brought up is: we shouldnt be picking this high again for awhile. Franchise quarterbacks can make even subpar teams into winners. With Tannehill its not hard to imagine us posting 9-7 seasons at the worst in years to come. There will always be exceptions to that rule, and perhaps 9-7 will net us a pick around 12th in the future, but by and large we should be picking in the second half of the draft in coming offseasons. Because of that, we really need to take advantage of this opportunity and take an impact player. There are several to choose from that should be available for us.
Offensive lineman fall every year. Riley Reiff and David DeCastro fell to the 20's last year. Anthony Castonzo and Gabe Camiri fell the year before that. Bryan Bulaga the year before that. Etc, etc, etc. We will have another chance to draft a tackle if we really need it in the future. We might not have a chance to grab a Carradine, Patterson, Austin, or others in future. We need difference makers and we need them right now. We didnt acquire all those extra picks for free, we traded away some very talented players. We must upgrade the level of talent on this roster.
Article on the modern importance of the left tackle here: