Insects also have muscles in certain locations throughout their bodies. You'll find the exact same structures in similarly structured insects, just on a smaller scale. Honestly I have no idea what you're talking about because they both have muscles and both have open circulatory systems, both will solidify into "meat" when cooked. I'm not sure what you're suggesting meaningfully distinguishes them here other than their taxonomic classifications and their size.
While it is inaccurate to characterize crustaceans as bugs, they are arthropods and share an enormous amount of anatomical and psychological features with insects. Both have open circulatory systems and use hemolymph to hydraulically operate their limbs. That "meat" that you're talking about is only really visible after cooking, and consists mostly of denatured and congealed hemolymph.