Colorado is just earlier in the process. Let's see where they stand after they need to extend some upcoming free agents.
Tampa is not in that great of shape. They just throw whatever they want on LTIR to hide it and circumvent the cap all the time. Lou will do the same when the time comes. Kucherov, Stamkos, Point, Hedman, McDonagh, Vasilevskiy, Seabrook on LTIR - all have long-term deals by your definition. Not that these are bad deals, but they strap up a TON of cap space and they have a ton of contracts coming up in the next couple of years.
Boston does do it well.
To me, the message I am getting from you is not really about term, but more about term for level of talent. You think term should only be used on top stars. Pelech/Pulock - top pair defenders - term is fine. Bailey-Nelson-Lee-Palmieri - term not worth it because you don't think they are up to that level. If that is the case, that is where we disagree. Isles are not built on top talent but on strong 1-4 lines. I would personally rather a full team of solid talent than a team of superstars surrounded by fill-ins. Colorado has both because they are early in the process and have made some shrewd moves but their time of reckoning will be coming soon. Tampa has gotten away with some stuff manipulating the cap to have top talent and depth. Boston struggled with depth last year. It is tough to have both. It is easier to have less players on term though when you just give top players term. However, that doesn't mean you are in a better cap position - those top players take up as much if not more than the Isles having the depth that they do.